Evaluation of physicochemical and functional properties of protein isolates from 5 edible mushroom species

Edible mushroom proteins are the promising ones with the advantages of complete essential amino acid profile and multiple functional activities. To reinforce their applications in functional food development, this study comprehensively evaluated the physicochemical and functional properties of protein isolates from 5 mushroom species, i.e., Pleurotus eryngii (PEP), Pleurotus ostreatus (POP), Lentinula edodes (LEP), Flammulina velutipes (FVP) and Hypsizygus marmoreus (HMP). Results showed that PEP, LEP, FVP, POP and HMP exhibited better protein solubility (PS), water holding capacity (WHC), emulsification activity index (EAI), and foaming capacity (FC) than those of soybean protein and pea protein isolates (PPI). PEP (51.95%) and POP (49.15%) had a higher amount of β-sheet structure. Principal component analysis and correlation analysis showed that the seven proteins could be divided into 3 clusters, and WHC, EAI and FC were significantly positively correlated with PS and β-sheet. The least gelation concentration of PEP (16%) and FVP (16%) at pH 6.0 and 7.0 was similar to PPI, and PEP showed better hardness, springiness and rheological properties than other proteins gels. Overall, our study showed that 5 edible mushroom proteins possessed excellent functionalities (except for gelling capacity), which provided novel insights on unexploited sources of mushroom proteins used as protein-based foods in the food industry.